Three-fourths of Illinois counties have cancer rates higher than the national average. Those counties also have an average pesticide use rate nearly 25% higher than the state’s other counties.
This finding, based on an analysis of data from both the U.S. Geological Survey and the National Cancer Institute, is in line with national figures.
Of the 500 counties nationwide with the highest pesticide and herbicide use per square mile, 60% of those counties also had cancer rates higher than the national average of 460 cases per 100,000 people, according to a recent Investigate Midwest report in partnership with the Pulitzer Center’s StoryReach U.S. Fellowship and the Fund for Investigative Journalism.
In Illinois, the counties with the highest cancer rates are most often in the central part of the state, a high crop-growing region where pesticide and herbicide use is highest.
There also appears to be a correlation between high pesticide use and higher rates of cancer in many other states, including Missouri, Iowa and North Dakota.
Cancer is a complex disease and linked to multiple factors. But scientific research linking pesticides with certain types of cancers has been growing. A 2024 study in Frontiers in Cancer Control and Society claimed pesticides rivaled smoking in their potential to cause cancer.
Some Illinois lawmakers have pushed for stronger regulations on agrichemical use, including an unsuccessful push during the 2026 legislative session to require a 72-hour notice to nearby schools and parks before spraying.
“There was pretty stiff opposition from the ag industry,” said Kim Erndt-Pitcher, director of ecological health at the Prairie Rivers Network, referring to House Bill 1596. “But we all have a right to clean air and healthy places to live and play and work, and these chemicals are trespassing.”
Data Harvest (formerly Graphic of the Week) is Investigate Midwest’s way of making complex agricultural data easy to understand. Through engaging graphics, charts, and maps, we break down key trends to help readers quickly grasp the forces shaping farming, food systems, and rural communities. Want us to explore other data trends? Let us know here.
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